Earth moving device



Feb. 1fs,193s. RE CHQATE M 2,031,463

EARTH MOVING DEVICE lFilled Oct. 3, 1932 3 Sheets-Sheet 1 fr q lum l MIL J Il l N VEN TORS 07A TTORNEY.

Feb. 18, 1936, R. E.. cHoA'rE'E-r AL I 2,031,463 EARTH MovING DEVICE Filed oct. 5, 1932 :5 sheets-sheet 2 A TTORNE) Feb.- 18, 1936. R. E. cHoATE E-r Ar.

EARTH MOVING DEVIQE Filedy oct.l `5 1952 s sheets-sheet s BYl Patented Feb.` is, 1936 PATENT OFFICE EARTH MOVING DEVICE Roy E. Choate and Waldo E. Rodier, Cedar Rapids, Iowa, assignors to La Plant-Choate Manufacturing Co. Inc., Cedar Rapids, Iowa, a cor- A poration of Delaware Application October 3, 1932, Serial No. 635,895

7 Claims.

`This invention relates to earth moving devices and has particular relation to a means for absorbing shocks which affect the plow or plow manipulating mechanism of such devices.

We have observed that in earth moving devices where a. plow, a. scraper blade, or the like is movably supported with reference to the tractor or other prime mover, breakage of the supporting and actuating mechanism sometimes occurs. These breakages, for the most part, upon investigation have been found to be caused, not by any normal loading of the earth moving device, but by reason of abnormal loading or sudden changes in loading such as the shock occasioned by dropping the blade or which occurs because the blade,

in operation, strikes a rock or other obstacle. It

is possible to construct the parts of the device of heavier, stronger parts more able to meet these sudden stresses, but if this is done the machine becomes unwieldy, heavy and ineicient.

After considerable investigation and experimentation we have devised a means for absorbing the shock occasioned by sudden changes in the loading and have thereby avoided the necessity of providing heavy structures to meet these shocks. In a preferred form of our invention we provide a link in the plow-moving and actuating' mechanism having means to permit lengthening and shortening of the link and having springs for resiliently resisting such lengthening and shortening and thereby absorbing the shock occasioned by changes in loading or abnormal loading. y

A general object oi our invention is to provide in an earth moving device a means for absorbing shocks a'ecting the plow and plow'manipulating mechanisml of such devices.

A more specific object of our invention is to provide in a plow-raising and lowering system one or more resilient parts so located as to absorb shock affecting the system.

A still more speciiic, object of our invention is to provide, in a.v means for 'raising and lowering the plow of an earth moving device, a resilient link for absorbing the shock caused by sudden changes in the loading or by abnormal loading of the plow and the plow-raising and Vlowering means. y

A feature of our invention is the provision of a link of the above character which may be substituted for the usual link of such a device and in which the tension on the springs of the resilient link may be adjusted.

Another object oi our invention is to provide a link of the above character which has springs for absorbing the shock and separate guiding means so that the parts of the link are always in alignment.

Still another object of our invention is to provide a link .of the above character adapted to utilize multiple springs for absorbing the shock and tothereby increase the capacity of the link.

Other and further features and objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawings and following specication, wherein is disclosed several exemplary embodiments of the invention, with the understanding, however, that such changes may be made therein as fall within the scope of the appended claims without departing from the spirit of the invention. The device may be used or adapted for use for other purposes.

In the drawings:-

Figure 1 is a. view in perspective of an earth 2o moving device in which a shock absorber mechanism constructed according to one embodiment oi our invention is incorporated.

Figure 2 is a view in enlarged perspective of one link of a. shock absorbing mechanism con- 25 structed according to one embodiment of our invention. This link is substantially identical with the links shownin Figure 1.

Figure 3 is a view in enlarged perspective of a link constructed according to another embodiment of our invention. This link is provided with multiple springs for absorbing shock and the capacity of the link is thereby increased.

Figure 4 is a view partly in section and partly in plan of the link shown in Figures 1 and 2.

Figure 5 is a. view in section of the link shown in Figure 4 and taken along the line 5 5 thereof.

Figure 6 is also a View in section of the link shown in Figure 4 but taken along the line 6-6 thereof.

Figure 7 is a plan view of the link shown in Figure 3.

Figure 8 is a view in section of the link shown in Figure 7 taken substantially along the line 8-8 thereof.

Figure 9 is a view in section of the link shown in Figure 7 but taken along the line 9--9 thereof.-

Figure 10 is a view in perspective of one of the co-acting jaws of the body of the link shown in Figure '7. A

Figure 11 is a diagrammatic view showing the combined hydraulic and mechanical shock ab- Y sorbing system, and

Figure 12 is a view in perspective of the rear l of an. earth moving device in which a combined hydraulic and mechanical shock absorbing system constructed according to our invention has been incorporated. While shock absorbing links constructed according to our invention may vary widely in structure, the preferred forms here shown preferably consist essentially of three sets of parts, one set of parts including co-acting links or link portions adapted to slidingly engage one another and having means for pivotally engaging the lever arms of the plow-actuatingvmechanism. These links are resiliently held in an intermediate or neutral position by.two springs or two sets of springs, one set of which 'acts to bias the coacting links apart and the other set of which acts to bias the co-acting parts of the link together. Inasmuch as the parts of the link are thus resiliently held in a neutral position, any tension or compressive stress acts to separate or move together the parts of the link and such movement is resiliently opposed by the sets of springs. The third set of parts is comprised of one or more `rocls upon which the springs slideand which act to hold both sets of springs in a condition of mutual initial compression.

Referring now to the drawings there is shown at I I) generally, a tractor having sub-frames II on the opposite sides thereof upon which wheels I2 are rotatably mounted for supporting and driving a link belt I3 for 'supporting and moving the tractor. Brackets I4, one on each side of the tractor, are mounted upon the sub-frames II and these brackets serve as bearings upon which plowsupporting frames I6 are pivotally mounted. A plow I1, which may be of any suitable or desirable construction, is attached to the front ends o f the frames I6 and a pair of shoes I8 engaged upon the lower side of the front ends of the frames I6 serve to slide upon the ground and hold up the plow and the front end of the frames I 6 with reference to the ground when the plow is in lowered position.

A plow-actuating means for raising and lowering the plow, such as the hydraulic jack 2|, may be mounted upon the tractor in any desired position, but in the present instance the jack is pivotally mounted upon brackets 22 which are supported by a platform 23 at one side of the tractor. In the present instance a shaft 24 eX- tends across the rear of the tractor and is mounted thereon by means of a beam 25 which engages the transmission casing of the tractor motor, or any other suitable part of the tractor and which is secured to the platform 23. Lever arms 21, one on each end of the shaft 24, project upwardly therefrom to a position adjacent and to the rear of the brackets 28 on the rear upper ends of the frames I6, and in the ordinary construction links connect the upper ends of the lever arms 21 with the brackets 28 on frames I6.

A lever arm 29 is pivotally connected to a yoke 3| on the end of the piston rod 32 of the hydraulic jack 2I and the lower end of the lever arm 29 is engaged on the shaft so that movement of the piston rod 32 causes rotation of the lever arm 29 and shaft 24 to cause a corresponding rotation of the lever arms 21 to depress or raise the rear ends of the frames I6 to correspondingly lower andraise the plow I1 at the front of the tractor. The plow actuating mechanism and the tractor. construction are not the subject matter of the present invention except in connection with the shock absorbing mechanism hereinafter explained and therefore need not be further described.

In the embodiment of the invention shown in l lever arm 21.

Figures 1, 2, 4, 5, and 6 the link, indicated generally by the numeral 4I, is comprised of a pair of inter-fitting cylinders 42 and 43, in which springs 44 and 46 and a shaft 41 are housed. The inner cylinder 42 is provided with a yoke-like extension 48 which is drilled as at 49 in order that a bolt I may be used for rotatably pinning this portion of the link to a lever arm such as the 'I'he yoke is cored out as at 52 for lightness. If desired the opening 52 may be enlarged to such an extent that the total strength of the remaining portion of the metal of the yoke will be less than any other part of the plow actuating' mechanism so that in the event of an extremely violent change in loading this yoke portion, which may readily be replaced, will break, rather than some other more expensive and less easily repairable part.

The larger outside cylinder 43 is also provided with a yoke extension 54 which is drilled as at 56 so that a pin 51 may be employed to pivotally secure the upper end of the link to the bracket 28 on the end of the beam I 6. 'I-'he yoke 54 is also cored out as at 58 for lightness. The size of this opening may also be so chosen that the link will break at this point under excessive or destructive loading. A partition 6I extends across the lower end of the cylinder 42 at the junction of the-cylindrical portion. and the yoke portion and this partition is drilled at the center so that the rod 41 may pass through the partition. A pair of diametrically-opposed slots 62 are provided in the walls of the cylindrical portion of the link 42 and a partition 63 on the inside of the larger link 43 extends through these openings and encircles the shaft 41.

In assemblingr the shock absorber link the shaft 41 is passed through the opening in the partition 6I and the nut 53 screwed on to the end of the shaft 41. The spring 44 is then placed on the shaft and the link 43 placed over the link 42 so that the partition 6I bears against one end of the spring 44 and the partition 63 bears against the other end. The spring 46 is then placed on the shaft 41 so that it bears against the other side of the partition 63 and the cup-like cap 64 is placed on the end of the shaft so that it bears against the other end of the spring 46. The nut 59 is then screwed on to the end of the shaft to hold the assembly in place. The link 43 is provided with a large opening 66 in order that the spring 46 may be inserted in the cylinder of the link and for lightness.

When the link 4I is in place in the plow-actuating mechanism as shown in Figure 1 it is apparent that the link 43 is normally held in an intermediate or neutral position half-way down on the link 42. It is apparent also that if tension stress is applied to the link the partition 63 will be drawn up against the compression of the spring. Obviously the pressure of the spring is compressed until the spring reaches a state of complete compression at which point no further lengthening of the link may occur.

If a compressive stress is placed on the link the partition 63 moves toward the partition 6I thus compressing the spring 44. The more the spring 44 is compressed the greater becomes the resistance to shortening of the link until the spring bottoms when no further shortening of the link can occur. It is obvious that the stresses of compression and tension on the link 4I are absorbed by shortening and lengthening the link against the compression of the springs 44 and 46 respectively and that any sudden change in loading on the plowis absorbed by theshock absorbi ing link. By using a shock absorber link con-f structed according to our invention the'effects of sudden and excessive loading on the plow are absorbed and breakage ofthe parts of the plow actuating mechanism is prevented. If the loading becomes too excessive one of the easily replaceable yokes of the device breaks and breakageI of the more expensiveparts of the mechanism is prevented. Preferably before this occurs a by-pass valve 30 (see Figures 11 and 12) in the hydraulic control system controlling the flow of iiuid to, from, and in the hydraulic jack, opens to relieve the excess pressure on the jack lines and therefore the stresseson the plow actuating mechanism.

Not only do devices constructed according to our invention relieve and cushion the stresses on parts of the earth moving device under abnormal conditions, but they also cushion the parts under normal loading and thereby prolong the life of the machine.

In another'embodiment of the invention shown in Figures 3 and 'I to l0 inclusive a pair of link castings 42a and 43a are employed in place of the links 42 and 43. These castings are provided with yoke members 48a and 64a which are drilled so that pins lavand 51a may be employed for fastening the shock absorbers to the lever arm 21 and bracket 28. It is desirable that the two links 42a and 43a be slidably engaged with each other to prevent misalignment of the link while in operation and a tongue and groove arrangement for slidingly engaging the two links is employed.

In the preferred embodiment of the invention a grooved lug 1I isemployed on one part of the intertting portions of the link and a pair of tongues 12 are employed on the other part of the samejink. The links 420, and 43ar are complementary and are castfrom the same mold. It may readily be understood by reference to Figure 7 that the tongues 12 ofA one link t into the grooves of the lug 1l of the other link and that the tongues of the other link fit into the correspending grooves of the first link. The links 42a and 43a may therefore slidingly engage one lil) another and misalignment of the links with respect to one another in operation is prevented.

The' link 42a is provided with cupped outwardly projecting members 16 which are provided with openings 11 therethrough. Another pair. of oppositely disposed lugs 18 are also provided on the outer end of the link 42a and these lugs have openings 19 therethrough which are in line with lthe openings 11 in cupped members 16. -The link 43a is preferably made from the same mold as the link 42a and is thus provided with cupped members 16a and lugs 18a in the same manner as link 43a. The openings 11 in the cupped members 16 and 16a'and the opening 19 in the lugs 18 are suiciently enlarged by drilling that the shafts 8| slidingly engage Ythe lugs 18, but the lugs 18a are internally threaded and the end of each shaft 8l is provided with screw threads which have threaded engagement with the lugs 18a. The shafts may be pinned by means of pins 82 which pass through the lugs 18a.,

The shafts 8| extend through the lugs .16a,l16, and 18 and beyond the lugs 18 to a suiiicient space that springs .46a may be located on the shafts beyond the lugs. Nuts 59a are threaded on the ends of'the shafts 8| and secured in place by means of cotter pins 8%.- Cup-like washers 84 and .86 are disposed respectively between the springs 46a and the nuts 59a and between the springs and the lugs 18. A second set of springs c are disposed on the shafts- 8l between the cooperating cup-like lugs 16l and 16a.

By inspection of the' drawings it becomes apparent, that motion of the two halves of the lengths when they are forced together isl resiliently resisted'by the spring 44a while any stress which tends to pull the links apart is resiliently resisted by the springs 46a. It is apparent therefore that the link indicatedgenerally by the numeral 81 and shown in Figures 3 and 7 to 10 inclusive operates in substantially the same way as linkll hereinbefore described except that its capacity may be considerably greater because the space for the springs is practically unlimited and more springs can be used.

Although we have described several embodiments of our invention it is apparent that modifications may be made by thoseskilled in the art. Such modifications maybe made without departing from the spirit andA scope of our invention as set forth in the appended claims.

We claim as our invention:

l. In a tractor, a plow disposed at the front of the tractor, frames disposed one on each side of the tractor and pivotally mounted thereon for tilting movement, and operatively engaged to the plow at the' front ends thereof, a cross-shaft at the rear of the tractor, a power means for rotating the cross-shaft, a lever for connecting the cross-shaft with the power means, other levers connected to the cross-shaft and projecting to positions near'the rear ends of the frames, and shock absorber links disposed between and operatively connecting the last named levers and the rear ends of the frames.

2. In a shock absorbing mechanism for earth moving devices, a pair of inter-fitting links adapted for sliding movement with respect to one another, a shaft xed to one link and passing through suitable portions of the other link, a

second spring disposed between the free end of the shaft and the link through which the shaft passes.

3. In a shock absorbing mechanism for earth moving devices, a pair ofv inter-fitting, slidablyengaged links,` a pair of shafts secured to one link and slidably engaged with the other link, one set of springs disposed on the shaft between the links, and a second set of springs disposed between the spring disposed between the two links, and a l free ends of the shafts and the link in which the shafts are slidingly engaged.

4. In an earth moving device including a tractor, a pair of blade lifting frames mounted for pivotal movement one on each side of the tractor.,

Aactuating means for manipulating the frames comprising a rotatably mounted cross shaft at the rear of the tractor, power means for rotating the shaft, lever arms on each end of the shaft, and resilient means connecting the levers with the frames for transmitting motion of the shaft to the frames and for absorbing shock between the parts of the blade actuating structure.

5. In an earth moving device including a prime mover, a pair of blade lifting-frames mounted one on each side of the prime mover, actuating means including levers at the rear of the tractor for manipulating the frames, and a pair of resilient links connecting the levers to the rear of the frames whereby shock betweenthe parts is absorbed.

6. In an earth moving device including a prime mover, a pair of blade lifting frames mounted for pivotal movement one on each side of the prime mover, actuating means for manipulating the frames including levers one on each side of the prime mover at the rear thereof, and resilient means connecting the levers with the frames at the rear end ofthe frames for-transmitting motion of the levers to the frames and for absorbing shock between the parts of the frame manipulating structure.

7. In an earth moving device including a prime 10 mover. a. pair o1' blade lifting frames mounted i'o'r pivotal movement one on each side oi the prime mover and extending rearwardly from the pivot mounting, levers at the rear of the frames and of the prime mover operatively connected to the. prime mover, and resilient means connected between the levers and the frames for absorbing shock between the levers and the frames.

ROY E. CHOATE.

WALDO E. RODLER. 

